Women smell best to men when they are most fertile, study finds

The research claims to be the first to recognise a link between female scent and fertility. © KEYSTONE / PETRA OROSZ

Women who smell attractive to men are likely to be at the most fertile time of their cycle, researchers from Switzerland and Germany have found. 

“Women with high oestrogen and low progesterone levels are most attractive to men in an olfactory sense,” said lead researcher Daria Knoch in a statement on Tuesday, summarising research carried out by the University of BernExternal link, the University of Konstanz, and the Thurgau Institute of Economics. 

The new scientific work, published in the Proceedings of the Royal Society B, is the first to recognise a link between female scent and fertility.

In their study, 57 men rated the body smells of 28 women of naturally reproductive age who followed a strict dietary and behavioural protocol to prevent the results from being distorted. Body odour was collected overnight from each woman’s armpit using a cotton pad. The women’s hormone levels were also monitored from saliva samples. 

The men then evaluated the attractiveness of the odours rating them from 0 to 100 points. 

The researchers were also able to eliminate other factors that might influence body odour such as the stress hormone cortisol and certain genes that have an impact on the immune system. 

“Reproductive hormones are indicators of a woman’s fertility. And the higher their levels are, the more attractive the woman is to men,” said Lobmaier. 

The results “make sense” in terms of evolutionary biology, the authors concluded. 

“Lots of oestrogen and not much progesterone indicates high female fertility. According to evolution theory, men look for women with whom they can successfully reproduce.”